Today, Google processes about 3.5 billion searches per day. Because of its dominant market share, Google holds a vast archive of keyword searches that, when analyzed, provide an interesting glimpse into the key themes that have captured the world's attention over the years.

Visual Capitalist's Carmen Ang and Nick Routley show in the infographic below, using data from Google Trends going back 20 years, some of the top keyword searches since 2001.

Visual Capitalist's editorial team dug through hundreds of top trending search terms from global and U.S. data and hand-selected their top picks, which are featured in the graphic above.

Trending vs. Volume

Before diving in, it's worth emphasizing how top trending searches differ from popular searches, which are measured by sheer volume.

Trending searches are terms that have recently spiked in popularity. They focus on growth rather than total volume, and in this dataset, trending terms gauge year-over-year growth.

A good example is Donald Trump, who popped up in the news cycle during the 2016 presidential campaign. After the election, interest in Trump remained high. But his name doesn't pop up on the Google trends list after 2017, since by that point, search volume for Trump had plateaued.

What are the most popular Google search terms, by volume? To be honest, they're slightly less interesting than the top trending searches — YouTube is number one, followed by Facebook, then WhatsApp web.